1. Field of the Invention
This invention concerns an aircraft assembly tool and a method of manufacturing such a tool.
2. Discussion of Prior Art
Aircraft assembly tools are designed to support aircraft components while they are being worked on and to locate different components together in the correct relative positions during aircraft assembly. Traditionally, each different assembly process has required at least one dedicated assembly tool, which is produced specifically for a given set of components and which is designed to support the components in a particular manner so that assembly operations can be carried out without interference from the tool. Such assembly tools have had to be manufactured to exacting standards.
A conventional assembly tool comprises a rigid metal jig whose framework is constructed from welded box section steel. A plurality of pick-up devices is mounted on the framework for carrying the aircraft components during the assembly process, and these too are conventionally produced from welded steel parts.
Each assembly tool has to be specifically designed for the component to be supported, and the requirement in the aircraft industry for an aircraft component to be supported with a very high degree of precision means that every stage of construction of the conventional jig has to be carried out to very exacting levels of accuracy. This makes the production of such jigs time-consuming and costly, and they cannot easily be reconfigured for supporting different components, or repaired/adjusted so as to accommodate wear and tear.
As is evident, such an arrangement has significant drawbacks, not the least of which are the high tooling costs resulting from the requirement for a dedicated jig for each aircraft assembly process together with the levels of accuracy needed for producing each jig. Minor modifications in aircraft component design usually mean that a completely new pick-up device or arrangement thereof must be produced, causing further tooling costs and assembly delays. In addition, wear and tear or damage to a jig generally results in the need for a replacement since repairs and adjustments cannot readily be made whilst maintaining the necessary level of precision and integrity for the framework and the pick-up devices.
In spite of these drawbacks, the construction of such aircraft assembly tooling has remained essentially unchanged for almost fifty years.
There is thus a significant need for an aircraft assembly tooling system that is more flexible in design and more economic to produce and use.